# US 11,439,969 B2 · Accelerated cooling process for reactors

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- Number: US 11,439,969 B2
- Document ID: US11439969B2
- Status: Granted
- Kind: B2
- Application number: 17/008,249
- Filed: 2020-08-31
- Published: 2022-03-03
- Granted: 2022-09-13
- Earliest claimed: 2020-08-31
- Assignees: Chevron U.S.A. Inc.
- Applicants: Chevron U.S.A. Inc.
- Inventors: Maggie A. Eaves; Charles R. Davis, Jr.; Greg A. Mullek; Clay Duncan, Jr.; Jeff W. Johns
- Web page: https://patentgrep.com/patent/US11439969B2

## CPC

- B01J 8/0035: {Periodical feeding or evacuation}
- B01J 8/0278: {Feeding reactive fluids (for solid material B01J8/0015)}
- B01J 8/0285: {Heating or cooling the reactor (for tubular reactors in furnaces B01J8/062)}
- C10G 45/00: Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
- C10G 49/002: {Apparatus for fixed bed hydrotreatment processes}
- B01J 2208/00761: Discharging
- C10G 2300/4031: Start up or shut down operations
- C10G 2300/4093: Catalyst stripping
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C10G: CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION (cracking to hydrogen or synthesis gas C01B; cracking or pyrolysis of hydrocarbon gases to individual hydrocarbons or mixtures thereof of definite or specified constitution C07C; cracking to cokes C10B); RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES

## Abstract

A process for shutting down a hydroprocessing reactor and for removing catalyst from the reactor, wherein the reactor includes a quench gas distribution system. The process comprises shutting off hydrocarbon feed to the reactor, stripping hydrocarbons from the catalyst, and cooling the reactor to a first threshold reactor temperature in the range of from 375-425° F. (190-218° C.). At least a portion of circulating gaseous medium flowing to the reactor is then routed through a temporary heat exchanger and cooling the gas to not less than 40° F. (4° C.). Once cooled, mixing the cooled gas with the circulating gaseous medium flowing to the reactor. Continuing steps routing and cooling until a second threshold temperature is reached wherein the reactor temperature is in a range between 120° F. and 250° F. (49° C.-121° C.). The reactor can then be purged with N2 gas, followed by introducing water into the reactor via the quench gas distribution system. The catalyst can then be safely removed from the reactor.

## Claims

### Claim 1

A process for shutting down a hydroprocessing reactor and for removing catalyst from the reactor, wherein the reactor includes a quench gas distribution system, the process comprising:
a) shutting off hydrocarbon feed to the reactor;
b) stripping hydrocarbons from the catalyst;
c) cooling the reactor to a first threshold reactor temperature in the range of from 375-425° F. (190-218° C.);
d) routing at least a portion of circulating gaseous medium flowing to the reactor through at least one temporary heat exchanger and cooling the gas to not less than 40° F. (4° C.);
e) mixing the gas cooled in d) with the circulating gaseous medium flowing to the reactor;
f) continuing steps d) and e) until a second threshold temperature is reached wherein the reactor temperature is in a range between 120° F. and 250° F. (49° C.-121° C.);
g) after step f), purging the reactor with N2 gas;
h) after step g), and when the reactor is at the second threshold reactor temperature, introducing water into the reactor via the quench gas distribution system; and
i) dumping a catalyst slurry from the reactor, the catalyst slurry comprising the catalyst and the water.

### Claim 2 (depends on 1)

The process according to claim 1, wherein the first threshold reactor temperature is about 400° F. (209° C.).

### Claim 3 (depends on 1)

The process according to claim 1, wherein the second threshold reactor temperature is not greater than 200° F. (93° C.).

### Claim 4 (depends on 1)

The process according to claim 1, wherein step b) comprises circulating H2 gas through the reactor at a temperature at least 25° F. above a final operating temperature of the reactor.

### Claim 5 (depends on 4)

The process according to claim 4, further comprising:
j) at the termination of step g), quantifying the hydrocarbon content of the effluent discharged from the reactor; and
k) based on the hydrocarbon content, determining a lower explosive limit for the reactor effluent.

### Claim 6 (depends on 1)

The process according to claim 1, wherein step c) comprises circulating H2 gas through the reactor, and the process further comprises:
l) during step c), recording the carbon monoxide concentration of the effluent discharged from the reactor; and
m) if the reactor temperature falls below a nickel carbonyl threshold temperature while the recorded carbon monoxide concentration is above a carbon monoxide threshold, re-heating the reactor above the nickel carbonyl threshold temperature for a time period sufficient to thermally decompose nickel carbonyl.

### Claim 7 (depends on 1)

The process according to claim 1, wherein:
step c) comprises circulating H2 gas through the reactor, the reactor includes a quench gas distribution system, and during step c) at least a portion of the H2 gas is introduced into the reactor via the quench gas distribution system.

### Claim 8 (depends on 1)

The process according to claim 1, wherein:
the water introduced into the reactor according to step h) is at a temperature not less than 50° F., and
the water introduced into the reactor according to step h) cools the reactor to a reactor temperature not greater than 120° F.

### Claim 9 (depends on 1)

The process according to claim 1, wherein step h) comprises flooding the reactor with the water.

### Claim 10 (depends on 1)

The process according to claim 1, wherein the water introduced into the reactor according to step h) has a chloride content not greater than 50 ppm.

### Claim 11 (depends on 1)

The process according to claim 1, further comprising:
n) concurrently with step i), separating the water from the dumped catalyst slurry to provide separated water, and
o) recycling the separated water to the reactor.

### Claim 12 (depends on 1)

The process according to claim 1, wherein a portion of the catalyst is retained within the reactor as residual catalyst after step i), and the process further comprises:
p) vacuuming the residual catalyst from the reactor.

### Claim 13 (depends on 12)

The process according to claim 12, wherein the reactor includes at least one quench ring having a plurality of quench apertures therein, and the process further comprises:
q) after step p), supplying water to the quench ring; and
r) during step q), assessing the patency of the quench apertures based on the height of a water spout delivered from each of the quench apertures.

### Claim 14 (depends on 1)

The process according to claim 1, further comprising:
s) after step i), washing the reactor internals with pressurized water at a pressure less than 5,000 psi.

### Claim 15 (depends on 1)

The process according to claim 1, wherein after step h) the reactor contains aggregated catalyst, and the process further comprises:
t) after step i), hydro-drilling the aggregated catalyst.

### Claim 16 (depends on 1)

The process according to claim 1, further comprising:
u) after step i), separating the water from the catalyst slurry to provide separated water,
v) quantitatively analyzing the separated water for the presence of contaminants to provide quantitative contaminant data, and
w) based on the quantitative contaminant data, determining a schedule for releasing the separated water to a refinery waste water system.

### Claim 17

A process for shutting down a hydroprocessing reactor and for removing catalyst from the reactor, the process comprising:
a) shutting off hydrocarbon feed to the reactor;
b) stripping hydrocarbons from the catalyst at a temperature above the final reactor operating temperature;
c) cooling the reactor with H2 gas at a controlled reactor cooling rate, wherein the reactor includes a quench gas distribution system, and during step c) at least a portion of the H2 gas is introduced into the reactor via the quench gas distribution system and the reactor is cooled to a temperature in the range of from 375-425° F.;
d) routing at least a portion of circulating gaseous medium flowing to the reactor through at least one temporary heat exchanger and cooling the gas to not less than 40° F. (4° C.);
e) mixing the gas cooled in d) with the circulating gaseous medium flowing to the reactor;
f) continuing steps d) and e) until a second threshold temperature is reached wherein the reactor temperature is in a range between 120° F. and 250° F. (49° C.-121° C.);
g) circulating N2 gas through the reactor during at least one pressure/depressure cycle of the reactor;
h) after step g), introducing water into the reactor via the quench gas distribution system;
i) when the reactor is flooded with the water, dumping a catalyst slurry from the reactor, wherein the dumped catalyst slurry comprises the catalyst and the water;
j) separating the water from the dumped catalyst slurry to provide separated water;
k) optionally, recycling at least a portion of the separated water to the reactor;
l) after step i), vacuuming residual catalyst from the reactor;
m) after step l), assessing the patency of a plurality of quench apertures of the quench gas distribution system; and
n) washing at least one internal component of the reactor with pressurized water, wherein:
the controlled cooling rate during step c) is not more than 25° F. per 15 minute interval, and
the water introduced into the reactor during step h) has a temperature not less than 50° F. and a chloride content not more than 50 ppm.